document.write( "Question 320518: Two trains leave the same city at the same time, one going north and the other east. The northbound train travels 20 mph faster than the east bound one. If they are 300 miles apart after 5 hours, what is the speed of each train? \n" ); document.write( "
Algebra.Com's Answer #229645 by mananth(16946)\"\" \"About 
You can put this solution on YOUR website!
Two trains leave the same city at the same time, one going north and the other east. The northbound train travels 20 mph faster than the east bound one. If they are 300 miles apart after 5 hours, what is the speed of each train?\r
\n" ); document.write( "\n" ); document.write( "..
\n" ); document.write( "east bound train speed be xmph
\n" ); document.write( "north bound train = x+20 mph
\n" ); document.write( "east bound train after 5 hours - distance = 5x
\n" ); document.write( "north bound train after 5 hours - distance = 5(x+20)=5x+100
\n" ); document.write( ".
\n" ); document.write( "The distance is a hypotenuse of a right triangle with 5x & 5(x+20) as the legs\r
\n" ); document.write( "\n" ); document.write( "(5x)^2 +[5x+100]^2= 300^2
\n" ); document.write( "25x^2+[25x^2+1000x+10000]= 90000
\n" ); document.write( "25x^2+25x^2+1000x+10000=90000
\n" ); document.write( "50x^2+1000x-80000=0 ( divide by 50)
\n" ); document.write( "x^2+20x-1600=0
\n" ); document.write( "Find the roots of the equation x1 x2
\n" ); document.write( "x1= (-20+sqrt(20^2+6400)/2)
\n" ); document.write( "x1= 31.23 speed of east bound train
\n" ); document.write( "x2=(-20-sqrt(20^2+6400)/2)
\n" ); document.write( "x2=-51.23 ( ignor negative value\r
\n" ); document.write( "\n" ); document.write( "speed of north bound train = 51.23 mph
\n" ); document.write( "CHECK
\n" ); document.write( "..
\n" ); document.write( " \n" ); document.write( "
\n" );